Hydrocarbons, such as oil and natural gas, are obtained from a subterranean geologic formation by drilling a wellbore that penetrates the hydrocarbon-bearing formation. After a wellbore has been drilled, the wellbore may be “completed” before hydrocarbons are obtained. A sealing system, such as a packer, may be deployed in a wellbore as completion equipment.
A packer is a device having an initial outside diameter which is smaller than a wellbore in which the packer is implemented. The packer is positioned at a desired location within the wellbore. Then, a sealing element of the packer is expanded to create an increased outside diameter which forms an annular seal between the packer and a surrounding outer surface, such as a casing string or a wall of the wellbore.
The annular seal isolates the wellbore sections above the packer from the wellbore sections below the packer and may provide a mechanical anchor which prevents the packer from sliding inside the wellbore. Alternatively or additionally, the packer may have slips which are components which engage the surrounding outer surface to anchor the packer in position. Mechanically anchoring the packer is known as “setting” the packer.
A packer may be set in a cased wellbore or an uncased wellbore. The annular seal formed by the packer may be used to control production, injection or treatment. After a particular operation is complete, the sealing element and/or the slips may be retracted to enable the packer to be removed or moved to another location in the wellbore.
It remains desirable to provide improvements in packers and methods of setting packers.